1. Field of the Invention
The present invention relates to a toy having a propeller as a propulsive force and, more particularly to a device for inclining a propeller blade tip path plane in an orbit of a tip end of the propeller blade to produce a propulsive force for use in a toy helicopter or the like.
2. Related Art
In a toy helicopter or the like in which the rotation of a propeller lifts the fuselage and produces a propulsive force to fly the helicopter, propulsive force in a desired direction is obtained by inclining the tip path plane of the rotating propeller blade, thereby driving the helicopter.
The conventional device for inclining the tip path plane of the propeller blade is effected by various methods, one example of which is illustrated in FIG. 14.
Blades c of identical shape are symmetrically mounted on a rotation shaft b connected to a motor (not shown) mounted within a fuselage a. The blades c are provided at a base end of the rotation shaft with a flapping hinge or formed of a flexible material so that a flapping operation can be obtained by the buoyant force of the rotating blades in accordance with the rotational pitch thereof. A swash plate d is composed of two discs, which constitute a rotatable disc d1 and a non-rotatable disc d2, respectively. One end of each of the blades c is connected to this rotatable disc d1 through respective pitch links e.
The non-rotatable disc d2 of the swash plate d can be inclined by control rods f, and the rotatable disc d1 of the swash plate d can be inclined together with the non-rotatable disc d2.
When the swash plate d is inclined by operating the control rods f, the rotating blades c are periodically varied in pitch, so that the tip path plane of rotation of the blades c is inclined relative to the rotation shaft b by the flapping operation in accordance with the pitch of the blades c.
The conventional device for inclining the tip path plane of the rotating blades constructed as described above requires the inclining mechanism composed of the swash plate d, the pitch links e and the control rods f, and hence the device is complicated and the assembly operation is cumbersome.
Further, a model helicopter or the like is required to be of a small size and light in weight so as to more easily lift the fuselage to allow the helicopter to fly easily. In the case where the above complicated device is incorporated, these requirements are difficult to meet. Moreover, the overall cost is high.
The present inventors have proposed a propeller blade tip path plane inclining device for overcoming the aforementioned difficulties accompanying the conventional device, as disclosed in the coassigned U.S. patent application No. 07/610,652 (allowed on Dec. 16, 1991), U.S. Pat. No. 5,110,314.